In the discussion of the state of the art that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art.
A conventional blast-frag warhead inflicts damage by two primary methods. The first is the overpressure generated from the detonation of an explosive fill. The second is the formation and acceleration of metal fragments from the warhead case caused by the detonation of an explosive. Different targets exhibit varying degrees of vulnerability to these damage mechanisms. Materiel is more vulnerable to fragments and structures are more vulnerable to blast overpressure. Personnel are vulnerable to both. In light of this, general purpose bombs are usually of the blast-frag variety to ensure that a large target set can be held at risk with a single weapon.
In general, the damage radius for fragmentation is considerably larger than that for blast. Blast damage drops off as a function of distance to the 3rd power. The addition of precision delivery with blast-frag warheads enables a significant weapon system lethality overmatch against many targets. This overmatch has driven our adversaries to attempt to seek cover in civilian populations where our rules of engagement limit our ability to engage them. The rules of engagement are driven by the political motivation to limit collateral damage. Collateral damage is the unintended damage or destruction of life or property near a target. Thus a general purpose warhead that could limit collateral damage without compromising probability of kill would be highly advantageous.
Others have tried to create low collateral damage warheads by eliminating fragment formation by replacing a metal case with a fiber reinforced plastic one. The elimination of the fragments results in a warhead with a primarily blast damage mechanism. However, the permanent elimination of fragments limits the target set against which the weapon is useful and in essence a niche weapon. It increases the logistic trail and mission loadout complexity.